1. Field of the Disclosure
The present invention relates generally semiconductor processing. More specifically, examples of the present invention are related to semiconductor processing of stacked integrated circuit systems.
2. Background
As integrated circuit technologies continue to advance, there are continuing efforts to increase performance and density, improve form factor, and reduce costs. The implementation of stacked three dimensional integrated circuits have been one approach that designers sometimes use to realize these benefits. The advances in wafer bonding with very precise alignments make it possible to fabricate stacked chips on wafer-level. The possible applications could include logic chips that are bonded to memory chips, image sensor chips, among others. This offers the advantage of smaller form factors, improved performance, and lower costs.
A key challenge when implementing stacked three dimensional integrated circuit systems, which continue to get smaller and faster, relates to weak bonding interfaces between the stacked wafers. In particular, weak bonding interfaces in stacked three dimensional integrated circuits suffer from cracks and peeling as a result of the etching processes. As a consequence, etching through weak bonding interfaces of stacked integrated circuit chips may cause unreliable connections between the wafers, and therefore failures in the stacked integrated circuit systems.
Corresponding reference characters indicate corresponding components throughout the several views of the drawings. Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention.